MBIA was the busiest of the group, with option volume surging to 15 times greater than average. Investors snapped up the November 11 calls and the November 12s, paying $0.99 to $2.13 and $0.52 to $1.77, respectively, for large blocks.

Ambac , which normally trades about 6,000 contracts, saw volume of 76,817 and heavy activity in the January 1.50 and October 1 calls before closing the day up 19 percent to $0.95. It was the biggest winner in the group, though it has been trading for under $1 for most of the last year as investors doubted its ability to survive as a going concern.

Radian climbed 6.83 percent to $8.91 and saw volume of more than 22,000 contracts, dominated by call buying. A similar pattern also appeared in Assured Guaranty and PMI.

By contrast, the Financial Select Sector SPDR exchange-traded fund, which tracks the broader financial sector, fell 1.78 percent to $14.60. Large banks and brokerages have been leading the sector to the downside, following a pattern of weakness that has been in place for months as the economy deleverages and underwriting fees get squeezed.